A well known concrete form for molding a round concrete column has a shell made up of several wound layers of paper material which are bonded together. In forming columns of a shape other than round, such as a square column, it is conventional to assemble forms, such as wooden or steel forms, on the construction site.
Included in the patent art are U.S. Pat. Nos. 2,873,503, 2,991,533, 3,301,926, and 3,350,049, which disclose prefabricated concrete forms for molding a noncircular concrete column. These patents do not show a concrete form having an inner elongate cylindrical member with an integral opening of the desired cross section for the concrete column and a cylindrical exterior which is enclosed in a layer of plastic stretch film stretched in situ to place the inner member in compression to provide adequate strength to resist the outward pressure of the poured concrete.